4e. Capturing the Chart: HCT

When scanning the HCT chart, here is a checklist of things to consider:

1. Adjust the white point of the scanner so that the whitest patch in the chart has an RGB value of about 250. Be absolutely certain that its value is less than 255!
   
   
2. If your scanner control software has curves or other controls, make sure that there is a difference in RGB values between neighboring patches on the grayscale.
   
   
3. When scanning your real pictures under these same scanning conditions, you may wish to adjust the scanner white point slightly on an image-by-image basis so that the brightest white object in the image does not saturate.
   
   
4. The CD that is included with the HCT target contains additional advice on how to set up your scanner to get the best possible results with the target.